Simulation And Test Verification Technology Of Vehicle Frontal Airbag Inflating Process

The proper use of occupant restraint system can protect the passengers effectively, but incorrect use will do harm to passengers. If passengers are out of position, for instance, they do not use the safety belts or their initial position is too close to the steering wheel or the instrument panel, the occupants will possibly contact the airbag and hurt seriously while it has not deployed enough. So the safety regulations for OOP protection are strict in developed countries, and the research on OOP protection have been applied in the vehicle production. The research of OOP protection requires correct simulation process of inflating and deploying of vehicle airbags.As occupant protection technology in our country inproving step-by-step, the simulation technology of occupant restraint system becomes increasingly important. Because of the danger and complexity of physical experiment, methods to combine test and simulation are always used to improve the calculation efficiency and decrease the times of experiments. Recently, the simulation of the process of airbag's inflation and deployment is still immatured, but in allusion to simulation, its validity is very important during the match of vechicle occupant restraint system, so it needs to establish an accurate airbag model, analysis the dynamic characteristics of the deployment, simulate the inflation process reliably.However, how to establish efficient and accurate model is a critical technology. This paper bases on the front passenger airbag of two domestic-made cars, Vehicle A and Vehicle B, make a thorough research in establishment of an accuracy simulation model of airbag and test verification technology of airbag module.2. Scope of PaperFirstly, on basis of great amount of documents, this paper summarizes the research status and details of automobile airbag, introduces the species and functions of airbag, elaborate the working principle of airbag and sums up the development status of simulation technology of automobile airbag in our country.Secondly, it introduces some relative theories of simulation technology of airbag, bases on the software platform MADYMO to specify the uniform pressure method and gas flow method, and provides a theoretical basis for the postern text to establish simulation models.Thirdly, based on the front passenger airbag of two domestic-made cars, Aand B, it comprehensively utilizes three modeling methods to establish CFD simulation model based on gas flow method. It uses different modeling methods for four airbags, such as two drive airbags and two passenger airbags, and it conducts a preliminary validation for the results of dynamic calculation of these models.Fourthly, it established static test models for the airbag, verifies the kinematics characteristics of the simulation model and compares the UP model and CFD model. On this basis, it supplys the dynamic pounding experiment of the airbag model and sets up dynamic pounding experimental models to verify the dynamic characteristics of these models.Finally it identifies that the gas flow models have the advantage of reliability and accuracy in the process of inflation and deployment of airbag. Fifthly,based on the DAB of vechicle B, 5th percent female hybridâ…¢out of position is researched. Then the models of static oop experiment and dynamic crash are computed and the a reliability and advantage of CFD model are certified. At the same time, the neck injury of the OOP occupant of vehicle B is far larger than the provided value of regulation, so the airbag model can not protect the OOP occupant efficiently, it needs to be improved in the following work.3. Significance of PaperFirstly, the paper explores the front airbag simulation and modeling methods, after calibrating a great amount of parameters, reliable and stable CFD models of airbag ,which accumulate some valuable experience for the later simulation work, are established.Secondly, a few dynamic experiment proposals for the airbag mould are supplied, after carrying out these plans in the experiment, and finally the accuracy of the simulation model is calibrated through the results of the experiment. In this process, some experiences during the simulation which can supply some reference for the next relative researches are summarized.Thirdly, experiment needs the guide of simulation while simulation can not continue without the verification of experiment. This paper has great practical significance for the research of simulation and experimental design of airbag, it can be a helpful reference material for the exploitation of advanced occupant restraint system.